Tool changer for machine tool

ABSTRACT

A tool changing mechanism for a machine tool having a horizontal spindle. A rotatable magazine is provided with a plurality of guides for supporting and guiding a plurality of tool cartridges. Each cartridge is provided with a plurality of vertically aligned tools. The magazine is indexed to align a selected cartridge with a transfer station. The cartridge is shifted into the transfer station and is positioned to present a selected tool to a transfer mechanism for removal of the tool and insertion into the spindle. The tool is returned to the cartridge by the transfer mechanism after use. A tape controlled motor means coordinates the operation of magazine, cartridges, and transfer mechanism to provide for returning one tool while another tool is operating on the work.

United States Patent 1191 Sato et a]. Dec. 18, 1973 [5 TOOL CHANGER FOR MACHINE TOOL 3,613,225 10/1971 Sato et a1 29/568 [76] Inventors: Yoshikazu Sato, No. 1,026,

4 Chomo Shimotakaido Primary Examiner-Ramon S. Britts Suginami-ku; Makoto Sato, No. Atwmey jay Cantor 1-10, l-Chomo, Nakano, Nakano-ku, Tokyo, both of Japan [57] ABSTRACT 2 Filed; June 1 1971 A tool changing mechanism for a machine tool having a horizontal spindle. A rotatable magazine is provided [21] App!" 148,910 with a plurality of guides for supporting and guiding a us Application Data plurality of tool cartridges. Each cartridge is provided [62] Division of Ser. No. 804,220, March 4, 1969, Pat. f Pluramy of vet/many aligned tools: The i No. 3,715,801 zine is indexed to align a selected cartridge with a transfer station. The cartridge is shifted into the trans- 52 us. Cl. 211/1.5, 29/568 fer Station and is Positioned Present a selected 51 Int. Cl. A47f 3/08, B23q 3/18 to a transfer meehanism fer remevel of the and [58] Field of Search 211/15, 60 T; insertion into the Spindle The tee] is returned to the 29/568, 26 A cartridge by thetransfer mechanism after use. A tape controlled motor means coordinates the operation of [56] References cu magazine, cartridges, and transfer mechanism to pro- UNITED STATES PATENTS vide for returning one tool while another tool is operating on the work. 3,355,797 12/1967 Lohneis 29/568 3,355,798 12/1967 Drechsler 29/568 3 Claims, 6 Drawing Figures PATENIED DEC 18 ms SHEET 1 BF 2 PAIENTEUHEE 18 I975 sum 2 or 2 TOOL CHANGER FOR MACHINE TOOL This application is a division of application Ser. No. 804,220, filed Mar. 4, 1969, now US. Pat. No. 3,715,801.

This invention relates to a machine tool and more particularly to a tool changing mechanism therefor.

It is an object of this invention to provide a tool changing mechanism that has a large tool storage capacity and is small in size.

It is a further object of this invention to provide a tool changing mechanism as aforesaid that is automatically controlled by coded tape for selecting the tools in proper order from storage.

It is a further object of this invention to provide a tool changing mechanism as aforesaid comprising a simple mechanism that can be easily manufactured at low cost and willoperate reliably for long periods of time.

These and other objects of the invention will become manifest upon reading the following description in conjunction with the accompanying drawings wherein:

FIG. 1 is a view in elevation showingthe tool changing mechanism mounted on a machine tool,

FIG. 2 is an enlarged view partly in section showing details of the tool changing mechanism,

FIG. 3 is a segmental view partly in section taken along the line 3-3 of FIG. 1,

FIG. 4 is a view partly in section taken on the line 4-4 of FIG. 1,

FIG. 5 is a view similar to FIG. 3 with the tool cartridge removed, and

FIG. 6 is a plan view of the magazine.

With reference to the drawings there is disclosed a bed 2 having secured thereto a column 4 for mounting the tool changing mechanism and a spindle head 6 which carries the tool'spindle 8 and the driving transmission for controlling the rotation of the spindle. The spindle head is mounted for vertical movement along slides carried by the column and is driven to the desired vertical position by a power operated lead screw. A work table 10 is mounted for movement in mutually perpendicular directions, normal and transverse to the axis of sliding of the spindle head. An index table 12 is removably mounted on the work table for supporting a work piece. H

A mounting cylinder 14 is secured to an extension 16 of the column by bolts 18. A tool storage magazine 20 is rotatably mounted on the cylinder 14 by anti-friction bearings 22 and 24. Themagazine comprises a cylinder 26 formed with a plurality of circumferentially spaced ways 28 for slidably mounting tool holding cartridges 30. Each cartridge removably stores a plurality of tools 32 for release and return by the tool changing mechanism to be described below and is retained in the way 28 by means of a key 34 secured to the cartridge and slidably mounted in a key way 36 in cylinder 26. Each tool is releasably retained in a recess 33 by a spring 35. A servo motor 38 is drivably secured to a reduction gear transmission 40 which is mounted in cylinder 14 by means of bolts 42. A plate 44 is secured to transmission 40 and cylinder 26 by screws 46 and 48 respectively, to rotate the cylinder.

A split retaining ring 50, having separated ends 51 and 53, is secured to extension 16 by bolts 52 and extends into a way 54 in each of the cartridges to prevent vertical movement of the cartridges in ways 28 in all positions of rotation of the cylinder except in a transfer station, to be presently described, wherein a selected cartridge is removed from the magazine to position the desired tool for removal by the tool change mechanism for transfer to the tool spindle.

The transfer station comprises a pair of retaining castings 56, 58 secured to column 4 by screws 60. Each member is provided with a pair of key ways 62 for slidably guiding keys 64 secured to a nut 66. The nut is threadedly mounted on a threaded shaft 68 supported for rotation at the upper end by a bearing 70 and is attached at the lower end to be rotated by a servo pulse motor 72. A key 74 is secured to the nut and has a vertical depth equal to that of the ring 50 for engagement with the ways 54 of the cartridges and fits between ends 51, 53 when the cartridge is in a stored position in a way 28 and the nut is in the uppermost position. A key way 76 is formed in transfer 56 and is aligned with key way 36 to form a continuous guide for key 34 as the cartridge is moved from the storage position in a way 28 to the transfer station between guide members 56, 58.

A tool changing mechanism for removing and returning the tools stored in a cartridge is mounted on column 4 above the spindle head 6 on a pivot 78 to pivot in a plane normal to the main tool spindle 8 and for sliding along the pivot to move parallel to spindle 8. The body 80 of the mechanism is provided with a pair of converging ways 82 and 84 for slidably supporting tool changing arms 86 and 88 containing claws 90 and 92 for grasping the tools. Arm 86 and claw 90 remove the used tool and arm 88 and claw 92 mount the new tool.

Changing arm 86 for used too] changing, grasps the used tool B, and places it into a designated recess in the cartridge which is locked into the transfer position.

Changing arm 88 for new tool changing, grasps the new tool C from cartridge 30 and by motion of the tool changing mechanism bodily along the axis of the tool spindle removes tool C completely from the cartridge then by swiveling along the plane perpendicular to the axis with pivot 78 as its axis and by motion of arm assembly 88 along the side of tool changing mechanism body 80, positions new tool C to coincide with the axis of main tool spindle 8, the above series of motions of the tool changing mechanism is controlled in sequence with the tool changing operation of the machine tool by means of data tape control mechanism 94.

The invention as described above comprises a rotatable tool-cartridge holding magazine 20 rotated by the servo motor 38 through gear train 40, whereby magazine 20 holding a cartridge 30. containing new tool C is positioned at the transfer station, a locking device comprising a way 54 on the lower back side of the cartridge engages key 74 of nut 66 which fits lead screw 68 driven by the servo motor 72 to lower the cartridge to the designated transfer position. The new tool C now being in a predetermined plane, the tool changing mechanism 80 is turned on pivot 70 until the claw 92 of the new tool changing arm 88 is in the predetermined plane. The arm 88 is then moved along the way 84 of the mechanism 80 until the claw 94 grasps new tool C and, by forward movement of the mechanism 80 and arm 88 along the pivot 78 parallel to the axis of spindle 8, the new tool is removed from the cartridge. The arm 88 is now moved backward along the way 84 and the mechanism 80 is rotated in a counter-clockwise direction until arm 86 is directly over the axis of spindle 8, the arm and claw 90 being in lowered position along its way 82. The mechanism 80 with the arms 86, 88, is now moved rearwardly along the axis of pivot 78. When the machining operation is completed, the spindle head rises a designated amount and changing arm 86, positioned as described above, grasps tool 8" by means of grasping claw 90 after which the changing mechanism is moved bodily outwards along the axis of the main spindle 8 to remove tool B from the main spindle, arm 86 is now raised by moving along the way 82 of the mechanism, simultaneously arm 88 with new tool C is lowered on way 84 by moving towards the axis of the main spindle. When the tool is positioned on the axis, this sliding motion is stopped and the mechanism is moved bodily along the axis of pivot 78 with the tool along the axis of the main spindle to mount new tool C" in the machine. On completion of this operation, arm 88 is returned along way 82 of the mechanism. Main spindle head 6 with new tool C mounted therein is lowered to perform the designated machining operation on the work mounted on index table 12. During the machining operation, the tool changing mechanism is moved forward parallel to the axis of the main spindle and rotated in a clockwise direction and used tool changing arm 86 is slid forward to position the used tool 3" over vacant storage recess either in the cartridge from which the new tool was removed or in a different cartridge moved into the transfer position thereafter, the mechanism is moved backwards parallel the axis of the tool spindle to deposit the used tool into the recess, after which arm 86 is returned along way 82.

New tool changing arm 88 which now is empty after mounting new tool C in the machine is now free to remove a different new tool from cartridge 30 by bringing another designated cartridge with a designated tool into the aforedescribed transfer position" a new tool from a different cartridge can be selected.

As described above, this invention pertains to a method and apparatus comprised of a cartridge storage magazine which can be selectively rotated and which has mounted on its periphery a plurality of cartridges which can be moved into the proximity of the main tool spindle at a designated transfer station, and means for changing, by a tool changing mechanism, in the shortest possible time, a used tool mounted in the main spindle of the machine with a new tool held in the cartridge, whereby a plurality of different machining operations can be performed in a highly efficient manner, especially by arranging the cutting tools in the cartridges according to the sequence of the machining operations and thereby eliminating the necessity of changing cartridges until the full tool complement of a cartridge has been used and thus saving the time lost in removing a cartridge from the cartridge storing magazine. Also, the use of cartridges permits storing a large quantity of tools in small area, and the change-cycle can be short ened and its operation can be made accurate and positive.

What we claim is:

l. A tool changing mechanism comprising of a selectively indexed rotatable magazine which has a plurality of cartridge holding grooves formed on its periphery, cartridges mounted within said grooves, said cartridges holding a plurality of cutting tools in a row, and said grooves confining said cartridges to move only in a lengthwise direction in parallel to the axis of rotation of the magazine, a fixed positioned retaining-ring with a sector removed where removal of the cartridge from the magazine takes place, and a groove formed in the bottom backside of each cartridge to engage the aforedescribed retaining-ring, a nut assembly moving to stop at designated positions which has a key block protruding from its front surface said assembly positioned to engage the designated cartridge in the removed sector of the retaining ring at the nut assemblys upper-most position thus providing means to bring the cartridge down to a designated transfer position.

2. A tool changing mechanism for a machine having a rotatable spindle comprising,

a cylindrical magazine rotatable about its axis,

a plurality of elongated cartridges supported about the periphery of the magazine for slidable movement parallel to the axis,

each cartridge having a plurality of radially extending recesses along its length within which tools are removably received to be supported radially of the magazine,

means for sliding each cartridge, when located at a predetermined station by the magazine, to position a selected tool therein at a predetermined tool transfer point,

and means at said point for removing the tool from the cartridge and placing it in the spindle.

3. A tool changing mechanism according to claim 2, wherein the cartridges are all normally positioned at a predetermined location on the magazine during rotation thereof,

and means for locking the magazine againt rotation when a selected cartridge is slidably moved away from said location to move a selected tool toward said tool transfer point. 

1. A tool changing mechanism comprising of a selectively indexed rotatable magazine which has a plurality of cartridge holding grooves formed on its periphery, cartridges mounted within said grooves, said cartridges holding a plurality of cutting tools in a row, and said grooves confining said cartridges to move only in a lengthwise direction in parallel to the axis of rotation of the magazine, a fixed positioned retaining-ring with a sector removed where removal of the cartridge from the magazine takes place, and a groove formed in the bottom backside of each cartridge to engage the aforedescribed retaining-ring, a nut assembly moving to stop at designated positions which has a key block protruding From its front surface said assembly positioned to engage the designated cartridge in the removed sector of the retaining ring at the nut assembly''s upper-most position thus providing means to bring the cartridge down to a designated transfer position.
 2. A tool changing mechanism for a machine having a rotatable spindle comprising, a cylindrical magazine rotatable about its axis, a plurality of elongated cartridges supported about the periphery of the magazine for slidable movement parallel to the axis, each cartridge having a plurality of radially extending recesses along its length within which tools are removably received to be supported radially of the magazine, means for sliding each cartridge, when located at a predetermined station by the magazine, to position a selected tool therein at a predetermined tool transfer point, and means at said point for removing the tool from the cartridge and placing it in the spindle.
 3. A tool changing mechanism according to claim 2, wherein the cartridges are all normally positioned at a predetermined location on the magazine during rotation thereof, and means for locking the magazine againt rotation when a selected cartridge is slidably moved away from said location to move a selected tool toward said tool transfer point. 